Mckie etal
dryer



INVENTORS 7270/1445 G. MaK/a' 2 M5@ Cle/sr ATTORNEYS May 9, 1967 T. G. MCKIE ETAL DRYER Filed Feb. 3, 1965 ABY @fwr- W @Mfew United States Patent Office 3,318,6l9 Patented May 9, 1967 3,318,019 DRYER Thomas G. McKie and Elmer E. Crist, Beloit, Wis., assignors to Beloit Corporation, a corporation of Wiscousin Filed Feb. 3, 1965, Ser. No. 429,977 3 Claims. (Cl. 34-111) This invention relates to improvements in dryers for drying fibrous webs and more particularly relates to an improved felt training arrangement for paper machine dryers.

The dryers of paper machines usually consist in a series of rotatable drying cylinders arranged one after the other in two vertically spaced horizontally extending rows. The wet fibrous web is trained in a serpentine path partially about an upper drying cylinder and then downwardly partially about a lower drying cylinder and upwardly partially about a next succeeding upper drying cylinder and alternately about the lower and upper drying cylinders t the end of the dryer.

Separate felt runs are provided for the rows of upper and lower drying cylinders to hold the fibrous web to the cylinders as it travels thereabout from an upper to a lower cylinder and then from a lower to an upper cylinder throughout the length of the dryer line. A series of idlers between the rows of upper and lower dryer cylinders retain the felts to pass about their respective rows of dryer cylinders, and felt idlers train the felt from the last drying cylinder of a series of drying cylinders about a felt drying cylinder and back to the first drying cylinder of the series of drying cylinders, in a dry condition.

When training a web to the drying machine a narrow tail is usually threaded about the dryer drums by hand or by Sheehan Ropes. The tail frequently breaks and wraps around a felt roll and builds up on the roll to such an extent that the machine must be stopped to clean the tail, commonly termed broke, from the roll. The prob-` lem of wrapping the tail or broke around the felt rolls is particularly prevalent in the present day high speed machines, where a tail wrapping around a felt roll can build up excessively in a relatively short period of time.

A principal object of the present invention is to remedy the foregoing deficiencies in dryers by so arranging the felt rolls of a continuous dryer that a tail breaking from the web and carried along the drying line by the felt, will be on the outside of the felt, as the felt is trained from the drying line about its drying cylinder.

Another object of the present invention is to .improve upon the dryers heretofore in use by training the felt to its drying -cylinder with the outside of the felt trained over the felt rolls to and from the drying cylinder and the inside of the felt on the outside of the felt rolls to carry a tail or other foreign material, for discharge to a broke pit, with no attention from the operator of the machine.

A further object of the invention is to provide a traininfr means for training the felt from a dryer line to a drying cylinder and back to the advance end of the dryer line, in which the felt rolls are all on the inside of the felt drying loop, placing the inner side of the felt on the outside of the felt drying loop with no interference from the felt rolls.

A still further object of the invention is to provide a series of felt rows on the inside of the felt as it passes to and from the felt drying drum and arranging the top run of the felt in cascade relation with respect to the bottom run of the felt passing from the dryer drum, to effect the discharge of broke, which may be carried to the dryer drum by the felt, to the lower run of the felt to be discharged into the broke pit, as the felt is trained to the advance end of the dryer line.

These and other objects of the invention will more clearly appear as the following specification proceeds and with reference to the accompanying drawing wherein, the figure is a diagrammatic view in side elevation of a dryer line for drying fibrous webs as they come from the paper machine.

In the embodiment of the invention illustrated in the drawing, we have diagrammatically shown a dryer section of a paper machine in which a paper web 7 indicated by dashed lines travels from left t-o right and enters the dryer section as it leaves the nip of a press section formed between press rolls 8 and 9. As diagrammatically shown in the drawing, the web 7 is trained in a serpentine path to first pass around a first drying cylinder 10` in an upper row or of successively arranged drying cylinders'ltl, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32 and 34 and to then pass around a first drying cylinder 11 of a lower row of drying cylinders 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33 and 35. The web passes partially around the drying cylinder 10 and partially around the lower drying cylinder 11 upwardly and partially around the drying cylinder 12 and down and partially around the lower drying cylinder 13 and alternately around the -upper and lower drying cylinders to the end of the drying line, in a conventional manner. In threading the web around the drying cylinders 10 to 35 inclusive, the leading end of the web has a narrow tail which gradually widens to the full width of the web. This tail is either threaded by hand around the drying cylinders or is trained by Sheehan Ropes in a conventional manner, so the threading of the web need not herein be described in detail.

The web is maintained in engagement with a first top series of drying cylinders lil, 12, 14 and 16 by a felt 36, partially wrapped about said cylinders by idlers 37 disposed therebetween. In a like manner the web is maintained partially wrapped around a first bottom series of drying cylinders 11, 13, 15 and 17 by a felt 39 partially wrapped about said cylinders by idlers 40, 40, therebetween.

A second upper felt 41 maintains the web partially wrapped about the next succeeding series of top drying cylinders 18, 20, 22, 24, 26, 28, 3) and 32 and is partially wrapped about said cylinders by idlers 43, 43 disposed therebetween. A lower felt 44 is partially wrapped about the second series of bottom drying cylinders 19, 21, 23, 25, 27, 29, 31 and 33 by idlers 45 disposed between said drying cylinders.

The felts 36, 41, 39 and 44 are formed of an open type fabric for encouraging evaporation of moisture from the web, but also may be formed of plastic wire fabric such as used on Fourdriniers. A material such as a forarninous plastic wire or fabric of the type known as formex fabric permits moisture vapor to be driven out of the pockets, .and the fabric to be maintained clean and open.

The lower felt 39 has a lower run passing about an idler 46 at the outgoing side of the drying cylinder 17 and downwardly therefrom, with the outside of the felt passing about a felt idler 47 and the inside of the felt passing about a felt idler 48. From thence the felt passes about inside and outside felt idlers 49, 5t! and 51 to and about a felt drying cylinder 53 and around an inside felt idler 54 upwardly to an inside felt idler 55 training the felt to the drying cylinder 11.

In a similar manner the lower felt 44 passes about an inside felt idler 56 at the outgoing side of the drying cylinder 33 and downwardly therefrom about an inside felt idler 57. From thence the drying run of the lower felt passes about a series of felt idlers 58, 59, dil and 62 engaging the felt on the inside and outside thereof, and upwardly from the idler 62, partially about a felt drying cylinder 65. The felt then passes downwardly along the 3 drying cylinder 65 about inside felt idlers 66, 67 and 68 to be partially wrapped about the drying cylinder 19 and about the succeeding drying cylinders 21, 23, 25, 27, 29, 31 and 33 as previously described.

The training arrangement of the lower felts 39 and 44 from their respective drying cylinders to their respective felt drying cylinders 53 and 65 is a conventional training arrangement. With the lower felts the problem of broke wrapping around the felt rolls is negligible, since the broke which may be carried f-rom the drying cylinders by the lower felt 39 may pass along the outsides of the idlers 46 and 47 and fall into a broke pit 69. With the next succeeding lower felt, any broke between the inside of the felt and the drying cylinders will be carried along the outsides of the idlers 56 and 57 and fall into a broke pit 70.

The problem of preventing broke or the tail of the web from wrapping about the felt idlers, training the upper run of the felt to its felt dryer is considerably different from that of the lower run of the felt, particularly since in previous dryers the felt has been trained about the insides and outsides of its felt idlers with the result that where the inside of the felt, carrying broke therewith is trained about a felt idler the broke or tail frequently wraps about the idler to such an extent as to make it necessary to shut down the dryer and remove the broke therefrom.

In order to overcome the problem of tails or other debris being carried by the drying runs of the felts 36 and 41 and wrapping about the felt idlers, the sides of the felts 36 and 41 engaging the drying cylinders as they pass about the respective drying cylinders, are trained outside of their training idlers, to face the outside, as the felts leave the last drying cylinder of the lines of drying cylinders and pass to the first drying cylinders of the lines of drying cylinders, and are dried when passing from the last to the rst drying cylinders. The felts 36 and 41 are trained to have upper drying runs and to pass about drying cylinders 71 and 72 respectively, with lower drying runs passing from the drying cylinders to the leading drying cylinders of the rows of drying cylinders. Since the two felts are trained in the same manner a detailed description of the training means for the drying run ofthe felt 41 only will herein be described.

The felt 41 passes from the outgoing side of the drying cylinder 32 and is trained from said drying cylinder upwardly about felt rolls or idlers 73 and 74, training the felt so that the side of the felt engaging the drying cylinder 32. faces outwardly. From thence the felt is trained toward the drying cylinder 18 over felt rolls 75, 76 and 77. The felt then passes backwardly around the felt dry- :ing cylinder 72 to a lower felt drying run over idlers 78 'and 79. The felt then passes downwardly to and around a felt roll 80, to and about the web passing about the dr` ing cylinder l18.

The upper felt drying run is arranged in cascade relation with respect to the lower felt drying run by the felt roll 77 as it passes backwardly to and around the felt drying cylinder 72. Therefore, should a tail or other debris stick to the felt, which frequently happens during a threading operation, the tail will travel along the out- :side of the felt, as it travels about the idlers 73, 74, 75, 76 .and 77. As the felt reverses its direction of travel about :the idler 77, the tail will be thrown off the upper felt drying run downwardly onto the lower felt drying run, as .the lower felt drying run passes about the outsides of the ,felt rollers 78, 79 and 89. Should the tail or broke be carried about the drying cylinder 72 by the felt, the broke will pass directly about said drying cylinder, because the yaffinity of the tail to the felt is greater than its affinity to the drier surface of the drying cylinder v72, due to the higher moisture content of the felt.

Where the tail or broke is discharged from the upper felt run to the lower felt run, due to the cascade arrangement of the felt, as it passes to and from the felt dryer,

or where the tail passes around the felt dryer over the felt idlers 78, 79 and Si) and may adhere to the felt, as the felt passes around the felt idler roll 80, the tail will pass about the drying cylinder 1S. Where the tail passes about the drying cylinder 18, it is doctored from the drying cylinder by a doctor 81. The tail will then travel downwardly with the downwardly traveling felt reach of the lower felt 39 to the broke pit 69.

It is of course understood that when the tail breaks the web is not trained about the drying cylinders, so the tail or broke may readily be discharged to either broke pit 69 or 74).

It may here be seen that the felt rolls training the felt on its drying run are all on the inside of the felt and train the side of the felt passing about the drying cylinders to the outside. This makes it impossible for the tail to become wrapped around any of the felt rolls, since the tai'l is always separated from the felt rolls by the felt. The felt training structure just described, therefore, avoids the wrapping of a broken tail around a felt roll or rolls by the simple manner of training the felt, so that the tail is always on the outside of the felt rolls. This materially facilitates the drying operation, making it unnecessary to stop the dryer to unwrap the tail or lbroke from the felt rolls, and therefore cures the problem of wrapping a broken tail around the felt rolls, particularly disadvantageous in the present day high speed dryers, where a tail wrapping around the felt roll can build up to the point where it must be cleared from the felt roll in a very short interval of time.

While we have .herein shown and described one form in which the invention may be embodied, it may readily be understood that various modifications and variations in the invention may be attained without departing from the spirit and scope of the novel concepts thereof.

We claim as our invention:

1. In a drying apparatus for fibrous webs,

a series of drying cylinders,

felts passing partial-ly about said drying cylinders and maintaining a web in intimate contact with said drying cylinders,

a felt drying cylinder spaced above said drying cylinders,

a series of felt rolls training the felt from the outgoing drying cylinder to a position disposed above said feit drying cylinder and in advance thereof and backwardly to and partially about said felt drying cylinder,

a second series of felt rolls training the felt from said felt drying cylinder to the incoming of said drying cylinders,

said felt rolls all being disposed on the inside of the felt away from the side of the felt having contact with the drying cylinders to free said felt rolls from broke or other debris that may be carried by the felt as it leaves the outgoing drying cylinder,

said second series of felt rolls including a last felt roll training the felt to the incoming drying cylinder,

and a doctor in association with the incoming drying cylinder of the series of drying cylinders doctoring any broke from the incoming drying cylinder that may be carried to said drying cylinder as the felt passes about said last felt roll to said incoming drying cylinder.

2. The structure of claim 1,

wherein the felt rolls train the Aelt along an upper feit drying run to said feit drying cylinder and along a lower felt drying run from said felt drying cylinder and arranging the upper felt drying run in cascade relation with respect to the lower felt drying run as it passes about its drying cylinder, to effect .the discharge of lthe broke onto the felt drying run as it has passed about the drying cylinder.

3i. A drying apparatus for librous webs comprising:

a first series of rotatable drying cylinders arranged in vertically spaced rows and including upper and lower incoming drying cylinders and upper and lower outgoing drying cylinders,

a second series of rotatable drying cylinders forming a continuation of said first series of rotatable drying cylinders,

said second series of rotatable drying cylinders being arranged in vertically spaced rows and including upper and lower incoming drying cylinders and upper and lower outgoing drying cylinders,

individual upper and lower first and second felt runs in association with said first and second series of upper and lower rows of drying cylinders,

idler rolls partially wrapping the associated felt runs about said irst and second series of upper and lower drying cylinders,

a first series of felt rolls training the felt from the outgoing drying cylinders to the incoming drying cylinders of said upper and lower rows of said first series of drying cylinders, with the side of the felt facing said drying cylinders trained to face to the outside, to retain the broke to the outside of the felt rolls,

a second' series of felt rolls training the felt from the 25 outgoing drying cylinders to the incoming drying cylinders of said first series of upper and lower drying cylinders, with the side of the felt formerly facing said drying cylinders trained to face to the outside, to retain broke to the outside of the felt rolls, the space between said first and second series of lower drying cylinders together with the felt trained from the outgoing end of the first series of lower drying cylinders, forming a downwardly opening broke chute in alignment with the incoming drying cylinder of said second series of upper drying cylinders,

and a doctor in association with the incoming drying cylinder of the upper drying cylinder of the second series of drying cylinders, doctoring any broke carried by the felt run passing labout the felt drying cylinder of the second series of upper drying cylinders to the upper incoming drying cylinder of the second series of drying cylinders, and disposed above said downwardly traveling broke chute, to effect the discharge of `broke from said drying cylinder along said broke chute.

References Cited by the Examiner UNITED STATES PATENTS 1,122,282 12/1914 Kilberry 34-116 1,595,240 8/1926 Minton 34-117 X 2,060,945 11/1936` Mellentine 34-111 X 2,163,163 6/1939 Weston 34-118 FOREIGN PATENTS 626,748 9/ 1961 Canada. 724,438 1/ 1932 France.

14,66() 1914 Great Britain.

30 FREDERICK L. MATTESON, JR., Primary Examiner.

A. D. HERRMANN, Assistant Examiner. 

1. IN A DRYING APPARATUS FOR FIBROUS WEBS, A SERIES OF DRYING CYLINDERS, FELTS PASSING PARTIALLY ABOUT SAID DRYING CYLINDERS AND MAINTAINING A WEB IN INTIMATE CONTACT WITH SAID DRYING CYLINDERS, A FELT DRYING CYLINDER SPACED ABOVE SAID DRYING CYLINDERS, A SERIES OF FELT ROLLS TRAINING THE FELT FROM THE OUTGOING DRYING CYLINDER TO A POSITION DISPOSED ABOVE SAID FELT DRYING CYLINDER AND IN ADVANCE THEREOF AND BACKWARDLY TO AND PARTIALLY ABOUT SAID FELT DRYING CYLINDER, A SECOND SERIES OF FELT ROLLS TRAINING THE FELT FROM SAID FELT DRYING CYLINDER TO THE INCOMING OF SAID DRYING CYLINDERS, SAID FELT ROLLS ALL BEING DISPOSED ON THE INSIDE OF THE FELT AWAY FROM THE SIDE OF THE FELT HAVING CONTACT WITH THE DRYING CYLINDERS TO FREE SAID FELT ROLLS FROM BROKE OR OTHER DEBRIS THAT MAY BE CARRIED BY THE FELT AS IT LEAVES THE OUTGOING DRYING CYLINDER, SAID SECOND SERIES OF FELT ROLLS INCLUDING A LAST FELT ROLL TRAINING THE FELT TO THE INCOMING DRYING CYLINDER, AND A DOCTOR IN ASSOCIATION WITH THE INCOMING DRYING CYLINDER OF THE SERIES OF DRYING CYLINDERS DOCTORING ANY BROKE FROM THE INCOMING DRYING CYLINDER THAT MAY BE CARRIED TO SAID DRYING CYLINDER AS THE FELT PASSES ABOUT SAID LAST FELT ROLL TO SAID INCOMING DRYING CYLINDER. 